My 1993 Accord leaks coolant every once in a while from the left side of the car, between the block and the timing belt cover about halfway down the side of the motor.

 

Have you checked hoses....the bad thing about radiator leaks is it goes everywhere, have you pinpointed the leak to the driver side of the car? If so I would have said tranny return lines but thats on the passenger side I think. You may want to purchase a dying agent to pinpoint its exact location. Also when you say it leaks sometimes does that mean after its warmed up and the coolant has had a chance to circulate and expand?

 

Also, it could be your water pump going bad. it is located about right where you said. the coolent will come out of a "weeping hole" are you up to date on your timing belt? they usually change the pump along with the belts.